hi Peter,
Not a full answer to your questions but from my experience:
Xenial: Worked, except OTP functionality
Zesty: Worked except for DNS
Artful: Seems fully functional and stable on the fresh installed replica, my upgraded from Zesty rig (with the workarounds noted earlier in thread) Still has pki-tomcat bombing fairly frequently.
Most of them required some cajoling during install or upgrade due to broken installer components (like directories not being created in one case, /etc/pki/pki.version confusing postinstall in another), but most of these behaviours were captured as bugs too. It feels very close to being something that can be reliably deployed, so I don't think it needs a huge amount more TLC to make it more of a pleasure to install ;)
Cheers,
David